U.S. patent number 8,594,554 [Application Number 13/152,546] was granted by the patent office on 2013-11-26 for simplified belt seam skip in continuous web feed machines.
This patent grant is currently assigned to Xerox Corporation. The grantee listed for this patent is Venkata B Chivukula, Ron E Dufort, Roger G. Leighton, Kenneth P Moore, Frank A Porter, Bruce A Thompson, Todd M Uthman. Invention is credited to Venkata B Chivukula, Ron E Dufort, Roger G. Leighton, Kenneth P Moore, Frank A Porter, Bruce A Thompson, Todd M Uthman.
United States Patent |
8,594,554 |
Porter , et al. |
November 26, 2013 |
Simplified belt seam skip in continuous web feed machines
Abstract
A system that avoids any stopping or reversing of the web
direction in a continuous feed printer, instead maintaining
consistent process speed, only requiring a slowing and speeding up
of the web to cycle through the PR belt seam. This is done by
forming a web loop and then immediately flattening the loop after
passage of the seam through the transfer zone that includes two
transfer BTR rolls with alternating transfer operations, but
simultaneous transfer for short periods. Two vacuum assist rolls,
one located between the two bias transfer rolls controls the
formation of the web loop. A pair of nip forming rolls upstream of
the first transfer station and a second vacuum assist roll
downstream of the second transfer station control the size of the
loop.
Inventors: |
Porter; Frank A (Penfield,
NY), Moore; Kenneth P (Rochester, NY), Thompson; Bruce
A (Fairport, NY), Uthman; Todd M (Rochester, NY),
Dufort; Ron E (Rochester, NY), Chivukula; Venkata B
(Webster, NY), Leighton; Roger G. (Rochester, NY) |
Applicant: |
Name |
City |
State |
Country |
Type |
Porter; Frank A
Moore; Kenneth P
Thompson; Bruce A
Uthman; Todd M
Dufort; Ron E
Chivukula; Venkata B
Leighton; Roger G. |
Penfield
Rochester
Fairport
Rochester
Rochester
Webster
Rochester |
NY
NY
NY
NY
NY
NY
NY |
US
US
US
US
US
US
US |
|
|
Assignee: |
Xerox Corporation (Norwalk,
CT)
|
Family
ID: |
47261804 |
Appl.
No.: |
13/152,546 |
Filed: |
June 3, 2011 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20120308286 A1 |
Dec 6, 2012 |
|
Current U.S.
Class: |
399/384; 400/583;
399/303; 399/121; 226/7; 400/611; 399/305; 399/162; 399/66;
226/95 |
Current CPC
Class: |
G03G
15/1695 (20130101); G03G 15/167 (20130101); G03G
2215/00599 (20130101); G03G 2215/00455 (20130101) |
Current International
Class: |
G03G
15/00 (20060101); G03G 15/01 (20060101) |
Field of
Search: |
;399/384,305,162,297,122,121,301,303,308,387,388,394,395,66
;226/1,7,29,95 ;400/611,583 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Marini; Matthew G
Claims
What is claimed is:
1. A continuous web printing system having a photoreceptor belt
with a seam, comprising: a first transfer zone including a first
bias transfer roll for transferring a first image from the
photoreceptor belt to the continuous web, a pair of nip forming
rolls located in a position upstream of the first transfer zone, a
second transfer zone including a second bias transfer roll for
transferring a second image from the photoreceptor belt to the
continuous web, a first vacuum assist roll disposed between the
first bias transfer roll and the second bias transfer roll for
creating a loop in the continuous web, and a second vacuum roll
disposed near the second bias transfer roll for controlling the
size of the loop of the continuous web in order to synchronize the
transfer of images to the continuous web in relation to the seam of
the photoreceptor belt.
2. The system of claim 1 wherein the size of the loop is in
relationship to the width of the belt seam and other non-imaged
portions of the belt.
3. The system of claim 1 wherein the first bias transfer roll and
the second bias transfer roll are alternately operational as the
belt seam traverses the first and second transfer zones.
4. In a continuous web printing system having a photoreceptor belt
with seam and an image transfer zone having a first bias transfer
roll and a second bias transfer roll, and a vacuum assist roll
disposed between the first bias transfer roll and the second bias
transfer roll, a method of compensating for the movement of the
belt seam through the transfer zone comprising the steps of:
allowing the continuous web to move further than the seam portion
of the belt by forming a loop in the web through the transfer zone,
removing the web loop, and forming the web loop after the seam
passes the transfer zone, wherein the step of forming a web loop
with the vacuum assist roll includes the step of separating the
vacuum assist roll from the seamed photoreceptor belt to allow
space for a loop in the continuous web in preparation of the seam
arriving at the transfer station and including a set of nip rolls
and a second vacuum assist roll, the set of nip rolls and the
second vacuum assist roll controlling the size of the loop.
5. The method of claim 4 wherein the step of alternating the
operation of the first bias transfer roll and the second bias
transfer roll as the seam moves through the transfer zone includes
the step of activating the first bias transfer roll and
inactivating the second bias transfer roll for images transferred
before arrival of the seam at the first bias transfer roll.
6. The method of claim 4 wherein the first bias transfer roll is
inactivated and the second bias transfer roll activated as the seam
and other non-imaged portions of the belt pass the second bias
transfer roll enabling transfer of the next image after the seam
and other non-imaged areas of the belt.
7. The method of claim 6 including the step of disengaging the
first bias transfer roll and slowing the nip rolls to straighten
the web and relax the loop.
8. A continuous web printing system having a photoreceptor belt
with a seam, comprising: a first transfer zone for transferring a
first image from the photoreceptor belt to the continuous web, a
second transfer zone for transferring a second image from the
photoreceptor belt to the continuous web, and a vacuum assist roll
disposed between the first transfer zone and the second bias
transfer zone for creating a loop in the continuous web for
synchronizing the transfer of images onto the web in relation to
the photoreceptor belt seam.
9. The system of claim 8 wherein each of the first and second
transfer zones includes a bias transfer roll.
10. The system of claim 8 wherein the size of the loop is in
relationship to the width of the belt seam other unimaged areas of
the belt.
11. In a continuous web printing system having a photoreceptor belt
with a seam, a first image transfer zone, and a second image
transfer zone, a method of compensating for the movement of the
seam through the transfer zones comprising the steps of:
alternately operating the first image transfer zone and the second
image transfer zone while the seam moves through the zones, forming
a web loop between the first image transfer zone and the second
image transfer zone, and removing the web loop upon passage of the
seam through the transfer zone, the system including a vacuum
assist roll and a set of nip rolls and a second vacuum assist roll,
wherein the step of forming a web loop includes the step of
separating the vacuum assist roll from the seamed photoreceptor
belt to allow space for a loop in the continuous web in preparation
of the seam arriving at the transfer station, and the set of nip
rolls and the second vacuum assist roll controlling the size of the
loop.
12. The method of claim 11 wherein the step of forming a web loop
between the first image transfer zone and the second image transfer
zone includes the step of selectively adjusting the size of the
loop.
Description
BACKGROUND
1. Field of the Disclosure
This disclosed device and method relates generally to a transfer
station used in continuous web electrostatographic or xerographic
printing systems.
2. Description of Related Art
The use of BTR (Biased Transfer Roll) foam rollers, disposed in
contact with a portion of a photoreceptor, as well as transfer
blades and dicorotrons, are often used in the prior art to pull an
image from a PR belt or drum to paper. In continuous paper web
feeding, however, a difficulty in printing onto a continuous web
substrate is the fact that belt type photoreceptors typically have
a belt seam. To avoid the seam on the belt, in the prior art, It
has been necessary stop the web movement, reverse the web
direction, and then reverse direction again to maintain
synchronization of the PR belt and continuous web, as the seam
passes through the transfer station. This movement of the large
mass of the paper roll is a complex process that inhibits speed of
operation of the printing system and poses unnecessary risk of web
malfunctions.
It is known, as disclosed in U.S. Pat. No. 5,970,304, buffers and
dancer rolls are known for the buffering of web speed variations
and also the separation of the web from the nip to adjust the
relationship of the photoreceptor belt and web for facilitating the
transfer of images from the belt to the web. Also, current designs
generally require the continuous web to separate, stop, back up,
and reverse again and remerge with the PR belt in order to skip the
seam on the
Thus, in accordance to the present disclosure, a system is provided
that avoids any stopping or reversing of the web direction in a
continuous feed printer, instead maintaining more consistent
process speed. The only requirement is a moderate slowing and
speeding up of the web, in order to cycle through the PR belt seam.
This is done by forming an adjustable loop in the continuous web
and then immediately flattening the loop after passage of the seam
through the transfer zone. The transfer zone includes two transfer
BTR rolls with selective transfer operations. Two vacuum assist
rolls control the formation and size of the web loop. These
advantages allow a relatively simple operation to cycle through the
PR belt seam.
SUMMARY OF THE DISCLOSURE
According to the embodiments, the present disclosure provides
continuous, uninterrupted images on media, for example, labels,
while skipping the photoreceptor belt seam. Thus, there is provided
a continuous paper web feed system with a pair of alternating
biased transfer roll transfer zones. To compensate for occurrences
such as the seam on the PR belt, according to this disclosure, the
web continuously moves forward, without reversing, to allow for a
seam to pass. In particular, a changing web loop, between the
biased transfer rolls, is able to grow and shrink in every cycle of
the PR belt. The selective activation of the biased transfer rolls,
along with the changing web loop, permits continual movement of the
web in the forward direction and the synchronization of the images
on the belt with the web.
BRIEF DESCRIPTION OF THE DRAWINGS
Various of the above-mentioned and further features and advantages
will be apparent to those skilled in the art from the specific
apparatus and its operation or methods described in the example(s)
below, and in the claims. Thus, they will be better understood from
this description of these specific embodiment(s), including the
drawing figures wherein:
FIG. 1 illustrates a belt seam about to pass through the
articulating dual transfer zone with the web loop formed;
FIG. 2 shows the belt seam after passing through the articulating
dual transfer zone area;
FIG. 3 illustrates the status of the articulating dual transfer
zone area and the web loop, the belt seam having reached the
vertical top of the belt configuration the web loop having been
pulled flat; and
FIG. 4 illustrates the seam again approaching the articulating dual
transfer zone area and the web loop again formed.
DETAILED DESCRIPTION OF THE DISCLOSURE
In accordance with the disclosure, there is provided a system that
avoids any stopping or reversing of the continuous web direction.
Instead, a consistent process speed is maintained, only requiring a
slowing and speeding up of the web to cycle through the PR belt
seam. This is done by forming and then flattening a web loop, using
a pair of vacuum assist rolls, during the passage of the seam
through the transfer zone. The transfer zone includes two transfer
BTR rolls with both alternating transfer operations and
simultaneous transfer operations.
With reference to FIG. 1, in accordance with the present
disclosure, there is shown a seam compensation technique in a
printing system having a photoreceptor (PR) belt 10, moving in the
direction of arrow 12, the belt 10 having roll BTR 1 at 22 and a
second image transfer zone is illustrated by a biased transfer roll
BTR 2 at 24. A first vacuum assist roll Vac 1 at 26 is shown
between transfer roll 22 and transfer roll 24 and a second vacuum
assist roll Vac 2 at 28.
In FIG. 1, Vac 1 is the vacuum assist roll provided to maintain
control of a web loop, shown generally at 32 and to assist in the
formation of loop 32. Nip 1, rolls 16, 18 and Vac 2 are responsible
to control the size of loop 32. Vac 1 actually separates further
from PR belt 10, as illustrated, to allow space for a loop 32 in
the paper web. This is in preparation of the seam 14 arriving at
the transfer station.
It should be noted that the loop 32 is formed and collapsed during
a full PR belt 10 cycle of the seam 14 of the PR belt 10. This
allows for the seam to pass, yet maintain tight image transfer at
BTR 1 and BTR 2 and synchronization of the images on belt 10 with
the movement of web 20. The size of the loop is selective and can
be adjusted depending upon the printing system configuration.
It should be noted that prior transfer systems required the
stopping to the web, reversing direction of the web, to back up the
web, and restarting again the movement of the web 20 in the
original direction. All of this movement was necessary in the prior
art, in order to synchronize the transfer operation with respect to
the web movement in relation to the belt movement, in order to
account for the seam of PR belt.
In accordance with the present disclosure, there is no reversal of
direction for seam accommodation, merely the formation of a loop in
the web each time the seam passes as illustrated in the
figures.
Still with reference to FIG. 1, BTR 1 is on and engaged with web 20
and Images on the belt 10 are being transferred ahead of seam 14 at
the transfer zone at BTR 1. BTR 2 at the second transfer zone is
off. BTR 2 is shown, disengaged from the web 20. However, it might
be possible to have BTR 2 off and engaged with the web 20, but not
transferring images.
With reference to FIG. 2, as the last image before seam 14 is
transferred, BTR 1 is turned off and BTR 1 is moved away from the
belt 10 and BTR 2 turned on as the belt seam 14 passes. At this
point, images will now be transferred behind the seam 14 at the BTR
2 transfer zone. The loop 32 in the web 20 will make the web travel
further than the PR belt 10, skipping the seam 14 and any
non-imaged portion of the PR belt. Also, label widths that don't
fit perfectly around the belt have to be taken into account by the
loop 32. The longer web 20 travel distance, because of the loop 32,
matches the length of the PR 14 seam and any non-imaged portion of
the PR belt.
Once the first image after seam 14 is transferred at the transfer
zone of BTR 2, the control slows down rolls 16 and 18 and BTR 1
starts to straighten the web 20. Preferably, there should be about
1.5 seconds to accomplish this move. The web 20 needs to be flat as
shown in FIG. 3 before the seam reaches the top of the
photoreceptor. Vac 1 and Vac 2 are maintained at process speed so
there is no problem with image transfer at the BTR 2 transfer zone.
During this 1.5 second time period, the seam 14 will be moving
vertically to a not shown position at the top of the PR belt 10
configuration.
With reference to FIG. 3, once the web 20 is flat and before seam
14 arrives at the top of the PR belt 10, BTR 1 is engaged and Vac 1
moved to touching PR belt 10. BTR 1 is immediately energized and at
this time both BTR 1 and BTR 2 will be transferring images. After
the belt 10 travels a distance equal to the distance between BTR 1
and BTR 2, BTR 2 is shut off and moved away from the PR belt 10.
The seam, within an approximate 1.5 seconds will then travel to
In FIG. 4, the Vac 1, Vac 2, and BTR 2 speed is readjusted, slowed
down, to reform the loop 32, taking about 1.5 seconds. Then BTR 2
is moved closer to the PR belt 10, similar to FIG. 1. As the seam
14 approaches BTR 1, the components are ready to repeat the process
again.
It should be understood that the above disclosure for the handling
of a web seam is merely exemplary of different situations such as
avoiding test patches and different formats for label printing and
the disclosure is intended to cover a wide range of applications
dealing with continuous web printing and adjustment for situations
requiring a deviation from routine operation.
The claims, as originally presented and as they may be amended,
encompass variations, alternatives, modifications, improvements,
equivalents, and substantial equivalents of the embodiments and
teachings disclosed herein, including those that are presently
unforeseen or unappreciated, and that, for example, may arise from
applicants/patentees and others.
* * * * *